1. Field of the Invention
The present invention relates to an inter-network connection system in a communication system. In particular, it relates to an inter-network connection system for mutually connecting a plurality of signaling networks using a common channel signaling system.
The common channel signaling system is a system wherein a speech path control signal is transmitted and received between signaling offices through a signal link, independently from a speech path, and commonly utilized by a plurality of speech paths, whereby a connection control of the speech path is carried out. In this system, a common channel signaling network comprising by the signal link is configured independently and separately from a telephone network comprising by the speech path or a data communication network comprising by data communication paths. The connection control of the telephone network and the data communication network is carried out by this common channel signaling network. This signaling system has various advantages, and thus has recently become generally utilized.
For example, as shown in FIG. 17, a telephone switched network comprising a plurality of telephone offices 01 to 04 and a data communication network comprising a plurality of data communication offices 05 to 08, etc., are interconnected by separate communication lines, i.e., a speech path and a data communication path respectively, so that the communication system is configured thereby.
Usually, a telephone call is carried out by dialing an office code (for example, 01, 02, 03, or 04) assigned to each telephone office, and a data call is carried out by dialing the office code (for example, 05, 06, 07, or 08) assigned to each data communication office, whereby the interconnections between an originating terminal and a destination terminal are carried out, respectively.
The telephone office code and the data communication office code, etc., are determined, respectively, as separate communication networks on the basis of the original numbering plan. Therefore, an efficient transmission of a great amount of the data becomes possible in spite of variations in the communication network and administrative structures thereof, by introducing a common channel signaling system, for example, a CCITT signaling system No. 7 as advised by the CCITT (International Telegraph and Telephone Consultative Committee).
When such a common channel signaling system is adopted, the call connection may be carried out by configuring the common channel signaling network, independently from the telephone switched network and the data communication network, then transmitting information of the destination office which is to be connected between the signaling offices 1, 1i, 1j, 2, 2i, or 2j on the basis of the independent numbering plan.
When the signaling network is configured by a single administrative structure, the call connection is easily carried out by transmitting the information including an address (destination) information of the terminating signaling office, in the same way as with telephone switching or data is communicated.
However, when the signaling network is configured by a plurality of separate signaling networks, an inter-network connection between the separate signaling networks becomes necessary.
The inter-network connection system according to the present invention makes it possible to easily interconnect such common channel signaling networks developed independently by each region, each country, or each manufacturer.